Pneumatic conveyor

ABSTRACT

This invention relates to an air conveyor for conveying articles with a collar and a head arranged above that, in particular plastic bottles along a conveyor channel having two carrying strips arranged along the conveyor channel on which the articles are conveyed by suspending them from the collars, and having a head space having inclined side walls formed above the carrying strips. Air nozzles, which act upon the heads of the articles, are provided in the inclined side walls. This counteracts a tendency of the articles to become tilted or jammed together.

[0001] This invention relates to an air conveyor for conveying articles,having a collar and a head above that, in particular for conveyingplastic bottles according to the preamble of Claim 1.

[0002] Such an air conveyor is known from U.S. Pat. No. 5,161,919. Theinclined side walls of the head space here may prevent excessive liftingand thus also prevents jamming of the articles between the carryingstrips if the articles are high enough. However, this positive effectmust be seen against the fact that the air nozzles are necessarilysituated beneath the carrying strips and engage on the main body of thearticles. In addition, this requires a bulky and cost-intensive designdue to the air channel, which extends far downward, for supplying air tothe air nozzles, since cleaning of this air channel poses problems.

[0003] There is also a conveyor which is known from International PatentWO 9910263, where the conveyor has carrying strips above which there isa head space having a rectangular cross section with a filling pieceinserted into it. This filling piece is supposed to prevent an upwardmovement of the bottles. However, since the filling piece is insertedinto the head piece as a separate part, it creates gaps and/or fissuresand gradations with the walls of the head space, which is problematicalfrom a hygiene standpoint, because such regions may lead to permanentdeposits of microorganisms. However, microorganisms must be preventedabsolutely, especially in the beverage area in the case of bottles to befilled.

[0004] The object of this invention is to create an air conveyor, whichwill reliably prevent twisting or jamming of articles without anydisadvantages, in particular from the standpoint of hygiene and cost.

[0005] This object is achieved through the features given in thecharacterizing part of Claim 1.

[0006] Due to the fact that the air nozzles are arranged in the inclinedside walls of the head space, the conveyor channel or air channel may belimited to the space above the carrying strips. This results in ease ofcleaning and an inexpensive design. In addition, this arrangement of theair nozzles counteracts the development of jamming. Since the bottlesare lifted merely due to the design of the inclined side walls —withoutinserts, filling pieces or the like—this also ensures simple cleaningand an inexpensive design.

[0007] Exemplary embodiments of the device according to this inventionare described and explained below on the basis of the drawings, whichshow:

[0008]FIG. 1 a first exemplary embodiment of an air conveyor in aperspective, schematic, partial view;

[0009]FIG. 2 a second embodiment of an air conveyor in the same view asin FIG. 1;

[0010]FIGS. 3a through 3 b a detail from FIG. 1 in various embodiments;

[0011]FIG. 4 a schematic diagram to illustrate the functioning of theair conveyor according to this invention in breaking up log jams;

[0012]FIG. 5 a third exemplary embodiment of an air conveyor in avertical section.

[0013]FIG. 1 shows an air conveyor 1 with which the articles 2, namelyPET plastic bottles in this case, are to be conveyed. Such bottles havea collar 3 and a head 4, and a thread is provided on the head so that aclosure can be screwed onto it. The bottle 1 is suspended by its collar3 on carrying strips 6 a and 6 b. The carrying strips 6 a and 6 b borderthe head space 5 at the bottom, i.e., they define the space in which thehead 4 of the bottle is located during conveyance.

[0014] The head space 5 has inclined side walls 8 a and 8 b which forman angle in the upper area of head space 5, in particular an acuteangle. Due to the fact that the side walls 8 a and 8 b are inclinedinward, they may serve as a stop to limit the lifting or tilting of thebottles 2. If a bottle 2 is to be raised or tilted by the stream of air,by other bottles or by other means, the upper end of head 4 will strikethe side walls 8 a and 8 b from beneath and will thus limit the liftingor tilting movement even before the widened part of the neck of thebottle can become jammed between the carrying strips 6 a and 6 b. Thisis explained in greater detail below.

[0015] Air is blown into the head space 5 through air nozzles 9 in theform of flaps in the direction of conveyance 15, so that air acts uponthe bottles 2 in the head part 4 so that they are set in motion or keptin motion.

[0016] Above the head space 5 there is an air supply channel 10 which issupplied with air from an air pressure source, which is not described ingreater detail here. Air flows out of the air supply channel 10 throughthe nozzles 9 and thus exerts a force on the bottles 2 for theconveyance movement.

[0017] Additional optional lateral guide devices 11 are also shown inthe lower portion of FIG. 1; these serve to prevent the bottle 2 fromtilting laterally.

[0018] The conveyor channel 7 shown here thus includes at least the headspace 5 with its inclined side walls 8 a, 8 b as lateral borders as wellas the carrying strips 6 a, 6 b, which border the head space at thelower end.

[0019] Due to this design of the lateral essentially planar side walls 8a and 8 b as stops, an especially simple and inexpensive means ofmanufacturing the air conveyor is thus possible. Likewise, due to thesimple design, this yields a head space which does not have any fissuresor gaps in which microorganisms can persist, multiply and propagate.Cleaning of an air conveyor according to this invention is very simpledue to this design of the head space 5.

[0020]FIG. 2 shows another embodiment of an air conveyor 1′ according tothis invention. Functionally identical components are provided with thesame reference notation. Instead of a head space 5 having a triangularcross section, as illustrated in FIG. 1, the head space 5 in FIG. 2 hasan essentially semicircular or arc-shaped cross section. Here again, thecurved side walls 8 a and 8 b of the head space 5 form a stop to limitthe tilting and lifting of the bottle 2. Instead of an air channel 10having a rectangular cross section, an air channel 10 having a roundcross section is provided here. Any combinations of air channels 10 inFIGS. 1 and 2 with the head space cross sections from FIGS. 1, 2 and 3are possible within the scope of the present invention.

[0021] The conveyor channel 7 illustrated in FIG. 2 thus includes atleast the head space 5 with its round side walls 8 a, 8 b as well as thecarrying strips 6 a, 6 b, which border the head space at the bottom.

[0022]FIG. 3a shows a detailed enlargement of the air conveyor 1 shownin FIG. 1, in particular its head space 5. Bottle 2 rests with itscollar 3 on the carrying strips 6 a and 6 b arranged at the sides, so itmay move forward or in reverse along the carrying strips, depending onthe direction of the air flow in the head space 5. Air slits, airnozzles or other orifices 9 are provided in the side walls 8 a and 8 band are suitable for deflecting the stream of air onto the head 4 of thebottle 2. Due to the stream of air directed in this way, the bottle 2may be set in motion. The angle 12 between the side walls 8 a and 8 bamounts to approximately 90 degrees in the exemplary embodiment shownhere.

[0023]FIG. 3a also shows that the lateral carrying strips 6 a and 6 bare arranged essentially horizontally in the direction across the airconveyor, so that the collar 3 is in surface contact with the carryingstrips 6 a and 6 b when the bottle 2 is hanging down vertically. Due tothe carrying strips, which are arranged horizontally, the position ofthe bottle 2 in which it is hanging vertically downward is stabilized inparticular.

[0024] However, FIG. 3b shows an embodiment of this invention in whichthe carrying strips 6 a and 6 b are inclined inward at the bottom.Therefore, the collar 3 is only in point contact with one of thecarrying strips 6 a and 6 b. This facilitates a free back-and-forthpendulum swinging movement of the bottle 2. Another possibleimplementation would involve a combination of the inclined carryingstrips 6 a and 6 b as illustrated in FIG. 3b with the rounded lateralwalls 8 a and 8 b as illustrated in FIG. 2.

[0025]FIGS. 3a and 3 b also show the dimensions, which are important forthe design of the head space 5 as a stop for a bottle 2 which is to beconveyed. It should be pointed out that the distance between the headedge or the mouth edge of the bottle and the stop point P1 with avertical lifting movement is smaller than the length h1 of the neck ofthe bottle whereby the length h1 of the neck of the bottle here denotesthe distance between the bottom side of the collar 3 of the bottle andan imaginary peripheral line L on the neck of the bottle at the locationwhere the diameter of the neck of the bottle corresponds to the distancebetween the carrying strips 6 a, 6 b.

[0026] In addition, the distance a2 between the edge of the mouth andthe location on the wall of the channel where the head 4 comes to a stopat point P2 in a tilting motion is selected so that stopping occurs atan angle at which the widening neck of the bottle has not yet come to astop on the bottom side of the carrying strips 6 a, 6 b.

[0027]FIG. 4 illustrates a particular advantage of the air conveyoraccording to this invention, which results from the fact that the airnozzles are situated in the inclined side walls 8 a, 8 b of the headspace 5, i.e., at the height of the head 4 of the bottles 2, where thedirection of conveyance is indicated by the arrow 15. When there is alog jam of bottles 2 in the air conveyor 1, the bottles often becomefanned out as illustrated in FIG. 4. Due to deceleration of the bottles2 with the collar 3 on the carrying strips 6 a, 6 b, the body of thebottle 2 is deflected forward in relation to its head part 4. This issupported in particular by the following bottles 2, each of whichpresses with its body against the others. Due to the fact that thedriving air current acts in the area of the head 4 of the bottles, aforce is exerted on the head 4 in the direction of the arrow 13, so thatthis results in a directional torque 14 on the bottles 2. Thisdirectional torque results in a breakup of such log jams as illustratedin FIG. 4, which is thus a great advantage for long-term operation ofsuch an air conveyor. If such log jams do not automatically break up,manual intervention is necessary, but that is often associated withdelays in production and stoppage of machines that should be operatingcontinuously. Therefore, automatic breakup of log jams as illustrated inFIG. 4 is a great advantage.

[0028] This advantage is obtained in particular due to the design of theair conveyor head space 5 as a stop for the bottles 2. Due to thisdesign as a stop, the cross section of head space 5 has a relativelysmall area, so that there is a definite increase in pressure upstreamfrom the head of the bottle in the event of a log jam, because the aircannot flow further through the head space 5 through the narrow crosssection. Thus, especially in the case of a log jam, an especially highlog jam resolving force acts on the bottles due to the narrow crosssection.

[0029] As an alternative to the arrangement of air nozzles 9 alone inthe side walls 8 a, 8 b, air nozzles 9 may also be arranged in any otherpart bordering the head space 5. For example, this is illustrated inFIG. 2, where air nozzles are also shown in the upper part of the headspace 5, which connects the curved side walls 8 a, 8 b.

[0030] In the exemplary embodiments illustrated in FIGS. 1, 2 and 3, theside walls 8 a and 8 b are designed in one piece or are made of onecohesive part. In FIG. 1, for example, this is an angle having legs thatform the side walls 8 a and 8 b. FIG. 2 shows a portion of a tube forlimiting the head space 5 at the top. Due to the fact that the sidewalls 8 a and 8 b are made of a single part, any hygiene problems thatmight occur due to fissures and gaps in the area of the head space areprevented. Furthermore, such a head space which contains very few anglesis extremely easy to clean.

[0031] The side walls in FIG. 1 may be manufactured from a prefabricatedangle section, for example. It is also possible to manufacture the walls8 a and 8 b separately and then weld them together in the upper area ofangle 12.

[0032] For the PET bottles, which are used especially widely in thebeverage industry, have a head diameter of 25 mm and a head height of 21mm, including the collar (form PCO 20). The resulting geometry of thehead space 5 according to FIG. 3a yields an optimum transport function.The angle 12 between the side walls 8 a and 8 b amounts to 70 degrees,and the height of the head space 5 over the horizontal supportingsurface of the carrying strips 6 a, 6 b amounts to 45.5 mm. This resultsin a distance a1 of approximately 6.2 mm. Such an air conveyor 1″ isshown in detail in FIG. 5.

[0033] In the case of the air conveyor 1″ according to FIG. 5, the twoinclined side walls 8 a, 8 b are manufactured in one piece with anotherwise planar horizontal bottom part 16 of the air channel 10. Thismeasure also contributes toward low manufacturing costs and a hygienicdesign without gaps. On the bottom side, the carrying strips 6 a, 6 bare detachably mounted by means of screws and clamps on the bottom part16, which is at the same level as the neck collar 3 of the bottles 2.

[0034] The air nozzles 9 in this embodiment are limited to that part ofthe head space 5 which is beneath the point of contact P1. This resultsin an absolutely smooth continuous stop surface for the bottle head 4and reliably prevents the bottles from becoming stuck.

1. An air conveyor (1) for conveying articles (2) having a collar (3)and a head (4) above it, in particular plastic bottles, along a conveyorchannel (7) having two carrying strips (6 a, 6 b) which are arrangedalong the conveyor channel and on which the articles are conveyed asthey hang by their collars, having air nozzles (9) arranged along theconveyor channel to allow air to act on the articles, and having a headspace (5) designed above the carrying strips with inclined side walls (8a, 8 b), characterized in that the air nozzles (9) are provided in theinclined side walls (8 a, 8 b) of the head space (5) and they act uponthe heads (4) of the articles (2).
 2. The air conveyor according toclaim 1, characterized in that the inclined side walls (8 a, 8 b) of thehead space (5) with the air nozzles (9) are designed to be smooth on theinside.
 3. The air conveyor according to claim 1 or 2, characterized inthat the inclined side walls (8 a, 8 b) with the air nozzles (9) aredesigned as stops to limit the lifting or tilting of the articles (2).4. The air conveyor according to one of claims 1 through 3,characterized in that the head space (5) is designed with a roof shape.5. The air conveyor according to one of claims 1 through 3,characterized in that the head space (5) is designed in a rhomboid form.6. The air conveyor according to one of claims 1 through 3,characterized in that the head space (5) is designed in an arc shape. 7.The air conveyor according to one of claims 1 through 6, characterizedin that an air supply channel (10) is provided laterally and above thehead space (5) to supply blasting air to the air nozzles (9).
 8. The airconveyor according to one of claims 1 through 7, characterized in thatthe carrying strips (6 a, 6 b) are arranged essentially horizontally. 9.The air conveyor according to claim 4, characterized in that the angle(12) between the inclined side walls (8 a, 8 b) corresponds toapproximately 70 degrees and the height of the head space (5)corresponds to approximately 45.5 millimeters.
 10. The air conveyoraccording to one of claims 1 through 9, characterized in that the lowerlimit (16) of the conveyor channel (7) and/or the air supply channel(10) is situated at the height of the collar (3) of the articles (2),and the carrying strips (6 a, 6 b) are mounted on the essentiallyhorizontal lower side of the border (16).
 11. The air conveyor accordingto one of claims 1 through 10, characterized in that the air nozzles (9)are arranged in the area of head space (5), which is beneath thestopping point (P1) of the head (4) on the inclined side walls (8 a, 8b).